Ion Bernstein waves in a plasma with a kappa velocity distribution
Using a VlasovPoisson model, a numerical investigation of the dispersion relation for ion Bernstein waves in a kappadistributed plasma has been carried out. The dispersion relation is found to depend significantly on the spectral index of the ions, κ{sub i}, the parameter whose smallness is a measure of the departure from thermal equilibrium of the distribution function. Over all cyclotron harmonics, the typical Bernstein wave curves are shifted to higher wavenumbers (k) if κ{sub i} is reduced. For waves whose frequency lies above the lower hybrid frequency, ω{sub LH}, an increasing excess of superthermal particles (decreasing κ{sub i}) reduces the frequency, ω{sub peak}, of the characteristic peak at which the group velocity vanishes, while the associated k{sub peak} is increased. As the ratio of ion plasma to cyclotron frequency (ω{sub pi}/ω{sub ci}) is increased, the falloff of ω at large k is smaller for lower κ{sub i} and curves are shifted towards larger wavenumbers. In the lower hybrid frequency band and harmonic bands above it, the frequency in a lowκ{sub i} plasma spans only a part of the intraharmonic space, unlike the Maxwellian case, thus exhibiting considerably less coupling between adjacent bands for low κ{sub i}. It is suggested thatmore »
 Authors:

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 School of Chemistry and Physics, University of KwaZuluNatal, Durban 4000 (South Africa)
 Publication Date:
 OSTI Identifier:
 22218499
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physics of Plasmas; Journal Volume: 20; Journal Issue: 10; Other Information: (c) 2013 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BERNSTEIN MODE; BOLTZMANNVLASOV EQUATION; BOUNDARY LAYERS; CYCLOTRON HARMONICS; DISPERSION RELATIONS; DISTRIBUTION FUNCTIONS; ELECTROMAGNETIC RADIATION; IONS; LOWER HYBRID CURRENT DRIVE; LOWER HYBRID HEATING; MAGNETIC FIELDS; NUMERICAL ANALYSIS; PLASMA SHEET; PLASMA WAVES; POISSON EQUATION; THERMAL EQUILIBRIUM; VELOCITY